NMR analyses on N-hydroxymethylated nucleobases - implications for formaldehyde toxicity and nucleic acid demethylases.
Org Biomol Chem
; 16(21): 4021-4032, 2018 05 30.
Article
em En
| MEDLINE
| ID: mdl-29767200
ABSTRACT
Formaldehyde is produced in cells by enzyme-catalysed demethylation reactions, including those occurring on N-methylated nucleic acids. Formaldehyde reacts with nucleobases to form N-hydroxymethylated adducts that may contribute to its toxicity/carcinogenicity when added exogenously, but the chemistry of these reactions has been incompletely defined. We report NMR studies on the reactions of formaldehyde with canonical/modified nucleobases. The results reveal that hydroxymethyl hemiaminals on endocyclic nitrogens, as observed with thymidine and uridine monophosphates, are faster to form than equivalent hemiaminals on exocyclic nitrogens; however, the exocyclic adducts, as formed with adenine, guanine and cytosine, are more stable in solution. Nucleic acid demethylase (FTO)-catalysed hydroxylation of (6-methyl)adenosine results in (6-hydroxymethyl)adenosine as the major observed product; by contrast no evidence for a stable 3-hydroxymethyl adduct was accrued with FTO-catalysed oxidation of (3-methyl)thymidine. Collectively, our results imply N-hydroxymethyled adducts of nucleic acid bases, formed either by reactions with formaldehyde or via demethylase catalysis, have substantially different stabilities, with some being sufficiently stable to have functional roles in disease or the regulation of nucleic acid/nucleobase activity.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Purinas
/
Pirimidinas
/
Formaldeído
/
Nucleosídeos
Idioma:
En
Revista:
Org Biomol Chem
Assunto da revista:
BIOQUIMICA
/
QUIMICA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Reino Unido